JP5015225B2 - Aperture device - Google Patents

Description

  The present invention relates to a diaphragm device.

  Patent Document 1 discloses a diaphragm device that squeezes the aperture of an opening formed in a substrate with a plurality of blades. Power is transmitted from the step motor to the blades via the drive ring. Transmission of power from the step motor to the drive ring is performed via a tooth portion formed on the drive ring or a gear. Power is transmitted from the drive ring to the blades by engaging a drive pin formed in the drive ring and a cam groove formed in the blade.

JP 2005-275177 A

  The rotor of the step motor employed in the diaphragm device can be stopped at every predetermined step angle. A plurality of positions where the rotor can be stopped are set. When the rotor stops, the drive ring stops and the blades also stop. The aperture diameter of the opening is defined according to the stop position of the blade.

  The power from the rotor is generally transmitted to the drive ring by a gear or the like. Therefore, the rotation angle of the rotor and the rotation angle of the drive ring have a linear relationship. For this reason, since the interval between adjacent stoppable positions of the rotor is constant, the interval between adjacent stoppable positions of the drive ring is also constant.

  On the other hand, the interval between the stop positions of the blades that stop in conjunction with the stop of the rotor is set to be smaller as the aperture diameter is reduced. This is realized by moving the drive ring so that the drive pin of the drive ring moves away from the rotation fulcrum of the blade as the aperture diameter is reduced. This is because the larger the distance between the rotation fulcrum of the blade and the drive pin of the drive ring, the smaller the rotation angle of the blade around the rotation fulcrum with respect to the rotation of the drive pin at a constant angle.

  When the drive ring is deviated from the original stoppable position and stopped, the blades are also deviated from the original stop position and stopped, thereby affecting the aperture diameter. In particular, when the stop position is shifted in this way at the minimum aperture where the aperture diameter is minimum, the accuracy of the aperture diameter is greatly affected. In order to minimize the influence on the aperture accuracy of the aperture, the interval between the stop positions of the drive ring should be set as large as possible, and the distance between the rotation fulcrum of the blade and the drive pin of the drive ring at the minimum aperture should be as large as possible. It is desirable to set. By setting in this way, at the time of the minimum aperture, the interval between the stoppable positions adjacent to the blades is minimized compared to the interval between the stoppable positions adjacent to the drive ring. Thereby, even if the stop position of the drive ring is shifted at the time of the minimum aperture, the shift of the stop position of the blade is less affected.

  Here, the interval between the stop positions of the drive ring is constant over the entire movement range of the drive ring. This is because, as described above, the interval between the positions where the step motor can be stopped is also constant, and the drive ring generally transmits power from the step motor via a gear. Accordingly, if the interval between the stoppable positions of the drive ring is set as large as possible, the size of the entire drive ring moving range increases, and the size of the entire drive pin moving range also increases. Accordingly, it is necessary to increase the size of the cam groove of the blade engaged with the drive pin. Thereby, a blade | wing becomes large.

  As described above, if the accuracy of the stop position of the blade is maintained at the time of the minimum aperture that minimizes the aperture diameter, the moving range of the drive ring is enlarged, and the blade is also enlarged accordingly.

  Therefore, an object of the present invention is to provide a diaphragm device in which the blades are miniaturized while maintaining the accuracy of the stop position of the blades at the time of the minimum diaphragm that minimizes the aperture diameter.

  The object is to have a substrate having an opening, a tooth portion, a step motor that can be rotated and stopped at every predetermined step angle, a driven tooth portion that meshes with the tooth portion, and the power of the tooth portion. A transmission member that can be rotated and stopped by receiving the power, a drive ring that can be rotated and stopped by receiving the power of the transmission member, and a retracted position that is retracted from the opening by receiving the power of the drive ring or at least one of the openings A blade that can be stopped at a throttle position that covers the portion, the drive ring has a driven pin, the transmission member has a cam groove that engages with the driven pin, and the amount of rotation of the transmission member The relationship with the amount of rotation with the drive ring is non-linear and can be achieved by a throttling device.

  Since the rotation amount of the transmission member and the rotation amount of the drive ring are non-linear, even if the interval between the adjacent stopable positions of the transmission member is constant, the interval between the adjacent stopable positions of the drive ring is the cam groove. And the position of the driven pin. Thus, according to the aperture diameter, the accuracy of the stop position of the blade is ensured by increasing the interval between the desired adjacent stop possible positions of the drive ring, and without reducing the stop possible position by reducing the interval, The moving range of the drive pin of the drive ring can be reduced. Accordingly, the size of the cam groove of the blade that engages with the drive pin of the drive ring can be reduced, and a diaphragm device with a reduced blade size can be provided.

  In the above configuration, the distance between the minimum stop position of the drive ring at the time of the minimum stop at which the aperture diameter is minimum and the stopable position adjacent to the minimum stop position of the drive ring is other than at the time of the minimum stop. It is possible to adopt a configuration that is larger than the interval between adjacent stoppable positions of the drive ring.

  By setting the interval between adjacent stoppable positions of the drive ring at the time of the minimum aperture where the aperture diameter is minimum as large as possible, it is possible to ensure the accuracy of the blade stop position at the time of the minimum aperture. Further, by setting the interval between the stoppable positions adjacent to each other in the drive ring other than at the time of the minimum aperture as small as possible, the size of the entire movement range of the drive pins of the drive ring can be reduced. Thereby, the magnitude | size of the cam groove of the blade | wing engaged with the drive pin of a drive ring can be made small, and the size reduction of a blade | wing can be achieved.

  ADVANTAGE OF THE INVENTION According to this invention, the aperture device with which the blade | wing was reduced in size can be provided, maintaining the precision of the stop position of a blade | wing at the time of the minimum aperture | diaphragm | squeeze which becomes the minimum aperture diameter.

FIG. 1 is an exploded perspective view of the diaphragm device according to the embodiment. FIG. 2 is a front view showing an internal configuration of the diaphragm device after assembly according to the embodiment. FIG. 3 is a front view illustrating an internal configuration of the diaphragm device after assembly according to the embodiment. FIG. 4 is a cross-sectional view illustrating a part of the diaphragm device after assembly according to the embodiment. 5A and 5B are explanatory views of the reciprocating motion of the driven pin in the cam groove. 6A and 6B are explanatory views of the reciprocating motion of the driven pin in the cam groove.

  Hereinafter, a diaphragm device 1 which is a drive device according to the present embodiment will be described with reference to the drawings. FIG. 1 is an exploded perspective view of a diaphragm device 1 according to the embodiment. The aperture device 1 has a shutter substrate 10, a transmission member 20, a thin plate 30, five blades 40, a thin plate 50, a drive ring 60, a step in this order from the subject side when the upper side of the drawing is the subject side and the lower side is the imaging side A motor 70 and a shutter substrate 80 are included. When the diaphragm device 1 according to the present embodiment is employed in a camera (optical device), an imaging element (not shown) for forming a subject image is disposed on the imaging side.

  The transmission member 20, the thin plate 30, the blade 40, the thin plate 50, the drive ring 60, and the step motor 70 are housed between the shutter substrates 10 and 80. The shutter substrate 10, the thin plates 30 and 50, and the shutter substrate 80 have openings 11, 31, 51, 81 for defining optical paths, respectively, at the center. Note that the size of the openings is smaller in the openings 31 and 51 than in the openings 11 and 81. The power of the step motor 70 is transmitted to the plurality of blades 40 via the transmission member 20 and the drive ring 60. Details will be described later. The transmission member 20 and a drive ring 60 that is a driven member constitute a speed reduction mechanism 90, and the speed reduction mechanism 90 is provided between the shutter substrates 10 and 80.

  When power is transmitted to the blades 40, the plurality of blades 40 swing around a predetermined position. Thereby, the aperture diameters of the openings 11, 31, 51, 81 are adjusted. By adjusting the aperture, the amount of subject light incident on the image sensor is adjusted. The thin plate 30 is disposed between the transmission member 20 and the blade 40, and the thin plate 50 is disposed between the blade 40 and the drive ring 60. The thin plates 30 and 50 are arranged between the driving components in order to avoid interference of the scraping members. The thin plates 30 and 50 are formed in a sheet shape.

  2 and 3 are front views showing the internal configuration of the diaphragm device after assembly. 2 and 3, the shutter substrate 10 and the thin plates 30 and 50 are omitted. However, the opening 51 of the thin plate 50 is indicated by a broken line. 2 shows a fully opened state in which the blade 40 is retracted from the opening 51, and FIG. 3 shows a small aperture state in which the blade 40 faces the opening 51. FIG. 4 is a cross-sectional view showing a part of the diaphragm device after assembly.

  As shown in FIGS. 1 and 4, a motor chamber AC for housing the step motor 70 is formed on the shutter substrate 80. A blade chamber SC for housing a plurality of blades 40 is formed between the shutter substrates 10 and 80. The motor chamber AC is formed in a concave shape so as to protrude from the blade chamber SC toward the image forming side in the optical axis direction. As shown in FIGS. 2 to 4, the step motor 70 includes a rotor 72, a stator 74, a coil 76, and the like.

  The rotor 72 includes a cylindrical portion 722 formed in a cylindrical shape and magnetized with magnetic poles having different polarities in the circumferential direction, and a rotating shaft portion 723 formed in a pair with the cylindrical portion 722. The cylindrical portion 722 and the rotating shaft portion 723 are integrally formed by insert molding. The cylindrical portion 722 is made of a magnet resin. The rotating shaft portion 723 is made of a synthetic resin with good slidability. For example, the rotating shaft portion 723 is made of polyacetal resin. Further, the shutter substrate 80 is erected on a support shaft 87 in the motor chamber AC. The rotating shaft portion 723 is supported by the support shaft 87 so as to be slidable and rotatable. Thereby, the rotor 72 is supported rotatably.

  The fixed shaft 82 is disposed on the inner side of the drive ring 60 as shown in FIGS. Thereby, size reduction of the shutter substrate 80 in the planar direction is achieved. Further, as shown in FIG. 2, a plurality of notches 84 are formed on the outer periphery of the shutter substrate 80. The notch 84 avoids interference with the blade 40 in the fully opened state. Thereby, the size of the shutter substrate 80 is reduced.

  As shown in FIGS. 2 to 4, the stator 74 is formed in a U-shape when viewed from the front, and coils 76 are wound around both arms. The coil 76 is connected to a flexible printed board (not shown) so as to be energized. The stator 74 is excited by the energized state of the coil 76. The rotor 72 rotates by a predetermined amount by the magnetic attraction force and the repulsive force generated between the excited stator 74 and the rotor 72.

  As shown in FIGS. 2 to 4, the rotating shaft portion 723 is integrally formed with a tooth portion 724 that forms a rotor kana portion. The tooth portion 724 is rotated by the power of the step motor 70 by the rotation of the rotor 72. The thin plate 30 is formed with an escape hole 37 that allows the rotation shaft portion 723 to rotate as shown in FIG. The tooth portion 724 is engaged with the driven tooth portion 24 formed on the transmission member 20. As shown in FIG. 1, the transmission member 20 has a shaft hole 23 formed substantially at the center. As shown in FIGS. 1 to 3, the support shaft 83 formed on the shutter substrate 80 and the shaft hole 23 are engaged. In addition, the transmission member 20 is rotatably supported. A cam groove 26 is formed in the transmission member 20. Here, the transmission member 20 is formed in a sheet shape thinner than the thickness of the tooth portion 724 in the optical axis direction, that is, the tooth width of the tooth portion 724. Specifically, the thickness of the transmission member 20 is set to about 0.03 to 0.15 mm. Preferably, it is 0.05-0.10 mm. Here, the sheet-like material may be flexible or not. For example, it may be a polyacetal resin, a polyethylene terephthalate resin, or a metal that does not have flexibility. In this embodiment, the transmission member 20 is formed of a flexible sheet-like member. The driven tooth portion 24 is formed over a substantially half circumference of the outer periphery of the transmission member 20. The cam groove 26 is formed in an arc shape around the shaft hole 23. In other words, the cam groove 26 is formed between the driven tooth portion 24 and the rotation center of the transmission member 20.

  When the tooth portion 724 rotates, the transmission member 20 rotates due to the engagement between the tooth portion 724 and the driven tooth portion 24. When the transmission member 20 rotates, a driven pin (engagement pin) 66 that engages with the cam groove 26 rotates around the optical axis. The driven pin 66 is erected on the drive ring 60. When the transmission member 20 rotates clockwise from the fully open state shown in FIG. 2, the driven pin 66 revolves counterclockwise around the optical axis as shown in FIG. That is, the drive ring 60 rotates counterclockwise.

  The drive ring 60 is formed with drive pins 64 corresponding to the number of blades 40. The drive pins 64 are formed on the drive ring 60 with substantially equal intervals. Cam grooves 44 formed in the blades 40 are engaged with the drive pins 64. Further, as shown in FIG. 1, the blade 40 is formed with a shaft hole 42 and engages with a fixed shaft 82 formed on the shutter substrate 80. Thereby, the blade | wing 40 is supported so that rocking is possible by using the fixed shaft 82 as a fulcrum.

  As shown in FIG. 1, escape holes 14, 34, and 54 that allow the drive pins 64 to move are formed in the shutter substrate 10 and the thin plates 30 and 50, respectively. In each of the shutter substrate 10 and the thin plate 30, escape holes 16 and 36 that allow the driven pin 66 to move are formed. The escape hole 36 is formed in an L shape as shown in FIG. Each of the thin plates 30 and 50 is formed with relief holes 32 and 52 into which the fixed shaft 82 is inserted. A locking claw 19 is formed on the outer periphery of the shutter substrate 10, and a locking portion 89 that engages with the locking claw 19 is formed on the outer periphery of the shutter substrate 80. The diaphragm device 1 is assembled by the engagement between the locking claw 19 and the locking portion 89.

  When the drive ring 60 rotates counterclockwise from the fully opened state, the drive pin 64 moves counterclockwise around the optical axis. Accordingly, the blade 40 swings so as to approach the center of the opening 51 with the fixed shaft 82 as a fulcrum. In this way, the diameter of the opening 51 is adjusted. In addition, the diameter of the opening 51 can be continuously adjusted by controlling the rotational position of the step motor 70.

  As described above, the openings 31 and 51 are formed smaller than the sizes of the openings 11 and 81. The openings 11 and 81 have substantially the same diameter, and the openings 31 and 51 also have substantially the same diameter. Accordingly, the light amount in the fully opened state is defined by the openings 31 and 51.

  In the fully opened state shown in FIG. 2, the driven pin 66 contacts one end of the cam groove 26, and the plurality of drive pins 64 contact one end of the escape holes 14, 34, and 54, respectively. 3, the driven pin 66 contacts the other end of the cam groove 26, and the plurality of drive pins 64 contact the other ends of the escape holes 14, 34, and 54, respectively. As described above, the movement of the blade 40 is limited between the fully opened state shown in FIG. 2 and the small aperture state shown in FIG. In this way, the contact of each member at a plurality of locations prevents the load from concentrating on a predetermined part.

  As described above, the power from the step motor 70 is transmitted to the drive ring 60 through the single transmission member 20. Thus, since the power from the step motor 70 is transmitted to the drive ring 60 by the single transmission member 20, the number of parts is reduced. In the conventional diaphragm device, the power from the actuator is transmitted to the drive ring via a plurality of gears, but by transmitting the power by the single transmission member 20 like the diaphragm device according to the present embodiment, Since only the tooth portion 724 and the driven tooth portion 24 are engaged, the operating noise is reduced. Further, since the number of parts is reduced, the manufacturing cost is also kept low. In addition, weight reduction is achieved because the number of parts is reduced.

  Further, the cam groove 26 formed in each of the transmission member 20 and the drive ring 60 and the driven pin 66 are engaged, whereby the power from the step motor 70 is transmitted to the drive ring 60. Since the conventional diaphragm device employs a plurality of reduction gears, the hitting sound is loud and it is difficult to reduce the operating noise. However, since the power of the throttling device according to the present embodiment is transmitted by the engagement of the cam groove 26 and the driven pin 66 without using a gear, the operating noise is reduced as compared with the conventional one.

  The transmission member 20 is flexible and thinly formed into a sheet shape. For this reason, the contact area between the tooth portion 724 and the driven tooth portion 24 is small, and the transmission member 20 is further bent, so that when the tooth portion 724 and the driven tooth portion 24 are engaged, the cam groove 26 and the driven pin 66 The shock at the time of engagement is absorbed, and the operation noise is reduced as compared with the conventional diaphragm device. Further, the reduction device 90 is provided between the shutter substrates 10 and 80, so that the diaphragm device 1 is thinned in the optical axis direction.

  Since the operation sound is reduced in this way, for example, when the diaphragm device according to the present embodiment is adopted in a camera having a moving image shooting function, there is a risk that the operation sound of the diaphragm device is recorded at the time of moving image shooting. Can be avoided. In addition, since the number of parts is reduced, for example, when the aperture device according to the present embodiment is adopted in a portable electronic device, weight reduction can be achieved, and impact resistance performance can be improved thereby.

  Further, the transmission member 20 is formed in a thin sheet shape. Therefore, the diaphragm device is made thinner by a configuration different from the conventional one in which the reduction gears do not overlap in the optical axis direction. Here, it is conceivable to form a reduction gear that is used in a conventional diaphragm device thinly. A reduction gear employed in a conventional diaphragm device has a large-diameter tooth portion and a small-diameter tooth portion in the axial direction. Therefore, even when such a reduction gear is formed thin, the thicknesses of the large diameter tooth portion and the small diameter tooth portion are required.

  Further, as shown in FIG. 4, by using the sheet-like transmission member 20, the transmission member 20, the blade 40, and the drive ring 60 can be disposed within the thickness of the step motor 70 in the optical axis direction. In other words, the transmission member 20, the blades 40, and the drive ring 60 can be disposed directly beside the step motor 70. Furthermore, the transmission member 20 is thinner than the tooth width of the tooth portion 724. This also achieves a reduction in the thickness of the aperture device in the optical axis direction.

  As shown in FIGS. 2 and 3, at least a part of the transmission member 20 overlaps the blade 40 and the drive ring 60 in the optical axis direction. Thereby, the miniaturization in the plane direction perpendicular to the optical axis direction is achieved. Since the transmission member 20 is formed in a sheet shape as described above, even if a part of the transmission member 20 overlaps the blade 40 and the drive ring 60 in the optical axis direction, the optical axis direction is reduced in thickness. Is maintained. Further, the transmission member 20 and the drive ring 60 can be arranged so as to overlap in the optical axis direction because the transmission member 20 and the drive ring 60 transmit power by the engagement of the cam groove 26 and the driven pin 66. Because it is done.

  As described above, since the thinning is maintained, the diaphragm device according to the present embodiment is suitable for use in a small electronic device such as a mobile phone.

  Further, since the transmission member 20 can be disposed so as to overlap the blade 40 and the drive ring 60 in the optical axis direction, the size of the transmission member 20 in the planar direction can be increased. Thereby, the pitch circle radius of the driven tooth portion 24 can be increased. Thereby, the reduction ratio between the rotor 72 and the transmission member 20 can be increased. By increasing the speed reduction ratio, the power of the step motor 70 can be further decelerated and transmitted to the drive ring 60, thereby improving the positional accuracy of the blades 40. Therefore, the control accuracy of the aperture is also improved.

  As shown in FIGS. 1 to 4, the speed reduction mechanism 90 according to this embodiment includes a drive ring 60 that is a driven member and a transmission member 20 that transmits power from the step motor 70 to the drive ring 60. It is configured. The drive ring 60 has a driven pin 66 that is an engagement pin. Further, the transmission member 20 has a driven tooth portion 24 that engages with a tooth portion 724 that forms a rotor kana portion that is power from the step motor 70. Further, the thickness of the transmission member 20 is smaller than the tooth width of the tooth portion 724 and is formed in a flexible sheet shape. Further, the transmission member 20 has a driven tooth portion 24 to which power from the step motor 70 is transmitted, and a cam groove 26 that engages with the driven pin 66, and a support shaft 83 formed on the shutter substrate 80. And the shaft hole 23 are engaged and supported rotatably.

  With this configuration, the speed reduction mechanism 90 transmits the power from the step motor 70 to the drive ring 60 by the single transmission member 20, so that the number of parts is reduced and the number of meshing parts is reduced, and the operation sound is also reduced accordingly. To reduce. In addition, since the transmission member 20 is formed in a sheet shape thinner than the tooth width of the tooth portion 724, the speed reduction mechanism 90 is thinned. Further, since the transmission member 20 has flexibility, when the tooth portion 724 and the driven tooth portion 24 are engaged with each other, an impact at the time of engagement between the cam groove 26 and the driven pin 66 is absorbed, and the operation sound is further increased. Reduced. Moreover, since the number of parts is reduced, low cost can be maintained and weight reduction can be achieved.

Next, the configuration of the diaphragm device 1 will be briefly described again.
The step motor 70 has a tooth portion 724, and the rotor 72 can be rotated and stopped at every predetermined step angle. The transmission member 20 has a driven tooth portion 24 that meshes with the tooth portion 724, and can be rotated and stopped by receiving the power of the rotor 72. The drive ring 60 can be rotated and stopped by receiving power from the transmission member 20. The blade 40 can be stopped at the retracted position retracted from the opening 51 or the throttle position covering at least a part of the opening 51 under the power of the drive ring 60.

  The blade 40 stops in conjunction with the stop of the rotor 72. Therefore, the diameter of the opening 51 can be defined over a plurality of stages. FIG. 3 shows the diaphragm device 1 at the minimum diaphragm where the aperture 51 is the smallest. The transmission member 20, the drive ring 60, and the blades 40 are each set with a plurality of positions that can be stopped within the entire movement range. The interval between the positions where the blades 40 can be stopped decreases as the distance from the center of the opening 51 decreases.

  Here, the cam groove 26 is formed so that the relationship between the rotation amount of the transmission member 20 and the rotation amount of the drive ring 60 is non-linear. The reason is as follows. When the rotation of the two members is interlocked via the tooth portion, the meshing point of the two members does not move. However, since the driven pin 66 moves in the cam groove 26, the positional relationship between the driven pin 66 and the cam groove 26 changes depending on the rotation of the transmission member 20. For this reason, when the positional relationship between the driven pin 66 and the cam groove 26 is changed, the relationship between the rotation amount of the transmission member 20 and the rotation amount of the drive ring 60 becomes nonlinear. The shape of the cam groove 26 is also formed so that the relationship between the rotation amount of the transmission member 20 and the rotation amount of the drive ring 60 does not become linear.

The above configuration will be described in more detail. In the diaphragm device 1 according to the present embodiment, the cam groove 26 has an interval between the minimum diaphragm stop position of the drive ring 60 at the time of the minimum diaphragm and the stop position adjacent to the minimum diaphragm stop position other than at the time of the minimum diaphragm. The drive ring 60 is rotated so as to be larger than the interval between adjacent stoppable positions of the drive ring 60, and the interval between the stoppable positions of the drive ring 60 is set so that the blades 40 move from the retracted position to the throttle position. The drive ring 60 is rotated so as to increase as the drive ring 60 moves. As described above, the cam groove 26 is formed so that the interval between adjacent stoppable positions of the drive ring 60 varies even if the interval between the stoppable positions adjacent to each other of the transmission member 20 is constant.

  As described above, the rotation angle of the drive ring 60 with respect to the predetermined rotation angle of the transmission member 20 varies depending on the positional relationship between the cam groove 26 and the driven pin 66. Thereby, even if the interval between the stoppable positions adjacent to each other in the transmission member 20 is constant, the interval between the adjacent stoppable positions of the drive ring 60 varies depending on the positional relationship between the cam groove 26 and the driven pin 66. With this configuration, since the interval of the stoppable positions of the drive ring 60 can be changed by changing the shape of the cam groove 26, the movement range of the drive ring 60 is not unnecessarily increased, and the drive ring 60 The size of the cam groove 44 of the blade 40 engaged with the drive pin 64 can be reduced, and the enlargement of the blade 40 can be suppressed. Thereby, size reduction of the diaphragm | throttle device 1 can be achieved.

  The interval between the minimum stop position of the drive ring 60 at the time of the minimum throttle and the stopable position adjacent to the minimum stop position of the drive ring 60 is set larger than the interval of the stoppable positions adjacent to the drive ring 60 other than at the minimum stop. Has been.

  By setting the interval between adjacent stoppable positions of the drive ring 60 at the time of the minimum aperture where the diameter of the opening 51 is minimum as large as possible, the accuracy of the stop position of the blades 40 at the time of the minimum aperture can be ensured. The reason for this is that at the time of the minimum throttle, the interval between the stoppable positions adjacent to each other of the blades 40 is minimized compared to the interval between the stoppable positions adjacent to each other of the drive ring 60. This is because even if the position deviates from this position, the influence of the deviation of the stop position of the blade 40 can be reduced.

  Further, by setting the interval between adjacent stoppable positions of the drive ring 60 other than at the time of the minimum aperture as small as possible, the size of the entire movement range of the drive pin 64 of the drive ring 60 can be reduced. Thereby, the magnitude | size of the cam groove 44 of the blade | wing 40 engaged with the drive pin 64 of the drive ring 60 can be made small, and the enlargement of the blade | wing 40 can be suppressed. Thereby, size reduction of the diaphragm | throttle device 1 can be achieved.

  Further, the interval between the stoppable positions of the drive ring 60 increases as the drive ring 60 moves so that the blades 40 move from the retracted position to the throttle position. When the drive ring 60 deviates from the original stop position and stops, the larger the interval between the stoppable positions of the drive ring 60, the smaller the relative shift amount with respect to the stoppable position interval. By setting the interval between the positions where the drive ring 60 can be stopped to increase as the position moves to the aperture position, the relative shift amount of the drive ring 60 decreases as the position moves to the aperture position. Thereby, the influence on the blade | wing 40 by the shift | offset | difference of the stop position of the drive ring 60 in an aperture position can be made small.

  As shown in FIGS. 2 and 3, the distance D1 between the drive pin 64 and the fixed shaft 82, which is the rotation fulcrum of the blade 40, is greater when the blade 40 is in the throttle position than when it is in the retracted position. long. Even when the blade 40 is in the throttle position than in the retracted position, the distance D1 between the drive pin 64 and the fixed shaft 82 is longer, so even if the stop position of the drive ring 60 deviates from the original position. Since the influence on the deviation of the stop position of the blade 40 is reduced, the influence on the blade 40 due to the deviation of the stop position of the drive ring 60 at the aperture position can be reduced. Thereby, the aperture diameter of the opening 51 can be narrowed down accurately.

  As described above, as shown in FIG. 2, the distance D1 when the blade 40 is in the retracted position is short, and the distance D1 when the blade 40 is in the aperture position is long. Thereby, the movement amount of the blade 40 when moving to the retracted position corresponding to the rotation of the predetermined step angle of the step motor 70 moves to the aperture position corresponding to the rotation of the predetermined step angle of the step motor 70. It is larger than the moving amount of the blade 40 at the time. The diaphragm device 1 is configured such that when the stop position of the drive ring 60 deviates from the original position, the movement amount of the blade 40 is larger at the retracted position than at the diaphragm position. Here, as shown in FIG. 2, at the retracted position, the blade 40 is retracted with a sufficient distance from the opening 51. Therefore, it is possible to minimize the influence of the diaphragm accuracy due to the stop position shift of the drive ring 60.

  As shown in FIGS. 2 and 3, the distance D <b> 2 between the driven pin 66 and the support shaft 83 that is the rotation fulcrum of the transmission member 20 is shorter when the blade 40 is in the retracted position than when it is in the throttle position. . As described above, since the moving amount of the blade when moving to the retracted position is large, the drive ring 60 and the transmission member 20 are loaded when the blade 40 is moved to the retracted position. However, the distance between the driven pin 66 and the support shaft 83 that is the rotation fulcrum of the transmission member 20 is short when the blade 40 is in the retracted position. The shorter the distance between the driven pin 66 and the rotation fulcrum of the transmission member 20, the more the transmission member 20 can drive the drive ring 60 with less torque. Thereby, the several blade | wing 40 can be smoothly moved to a retracted position.

  Next, the reciprocation of the driven pin 66 in the cam groove 26 will be described. 5A, 5B, 6A, and 6B are explanatory views of the reciprocating motion of the driven pin 66 in the cam groove 26. FIG. 5A and 5B show a state in which the driven pin 66 is in contact with one end of the cam groove 26, and FIGS. 6A and 6B show a state in which the driven pin 66 is separated from one end of 23. 5B and 6B are enlarged views around the driven pin 66 of FIGS. 5A and 6A, respectively.

  6A and 6B show a state where the blade 40 is farthest from the center C of the opening 51. 5A and 5B show a state immediately before the blade 40 is farthest from the center C of the opening 51. FIG. When the transmission member 20 further moves counterclockwise from the state shown in FIGS. 5A and 5B, the drive ring 60 moves clockwise and shifts to the state shown in FIGS. 6A and 6B. That is, FIG. 5A, 5B, 6A, 6B has shown the state in the middle of the blade | wing 40 moving to a retracted position from an aperture position.

  As shown in FIGS. 5A and 5B, the driven pin 66 contacts the one end 26 a of the cam groove 26 immediately before the blade 40 is completely retracted from the opening 51. Here, an imaginary line connecting the center C of the opening 51 and the support shaft 83 is L. As shown in FIG. 5B, in this state, the virtual line L substantially passes through the center of the driven pin 66. From the state shown in FIGS. 5A and 5B, when the rotor 72 further rotates and the transmission member 20 rotates counterclockwise, the drive ring 60 rotates clockwise as shown in FIG. 6B. As shown in FIG. 6B, the driven pin 66 rotates in the clockwise direction CD, and the blade 40 is in the state farthest from the center C of the opening 51. At this time, the driven pin 66 moves away from the one end 26a by a distance CR to the other end side of the cam groove 26.

  In this manner, the driven pin 66 moves from the other end of the cam groove 26 to the one end 26a and contacts the one end 26a while the drive ring 60 rotates in the clockwise direction CD. Move to the end side. The driven pin 66 reciprocates part of the cam groove 26, thereby preventing the entire length of the cam groove 26 from increasing. Therefore, size reduction of the transmission member 20 is achieved. As a result, downsizing of the entire diaphragm device 1 is also achieved.

  Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and modifications and changes can be made within the scope of the gist of the present invention described in the claims. Is possible.

DESCRIPTION OF SYMBOLS 10, 80 Shutter board | substrate 11, 31, 51, 81 Opening 20 Transmission member 24 Drive tooth part 26 Cam groove 40 Blade 44 Cam groove 60 Drive ring 64 Drive pin 66 Drive pin 70 Step motor 72 Rotor 90 Deceleration mechanism AC Motor chamber SC Blade Room

Claims (9)

A substrate having an opening;
A step motor having tooth portions and capable of rotating and stopping at predetermined step angles;
A transmission member that has a driven tooth portion that meshes with the tooth portion, and that can rotate and stop by receiving the power of the tooth portion;
A drive ring that can be rotated and stopped by receiving the power of the transmission member;
A vane that can be stopped at the retracted position that retracts from the opening or the throttle position that covers at least a part of the opening by receiving the power of the drive ring,
The drive ring includes a drive pin for engaging the blade, and a follower pin,
The transmission member has a cam groove that engages with the driven pin;
The diaphragm device characterized in that the relationship between the rotation amount of the transmission member and the rotation amount of the drive ring is non-linear.   The distance between the minimum stop position of the drive ring at the minimum stop where the aperture diameter is minimum and the stopable position adjacent to the minimum stop position is adjacent to the drive ring other than at the minimum stop. The diaphragm device according to claim 1, wherein the diaphragm device is larger than an interval between the stoppable positions to be stopped.   The diaphragm device according to claim 2, wherein an interval between the stoppable positions of the drive ring increases as the drive ring moves so that the blade moves from the retracted position to the throttle position.   The distance between the drive pin and the rotation fulcrum of the blade is longer when the blade is in the throttle position than when the blade is in the retracted position. Squeezing device.   5. The diaphragm device according to claim 4, wherein the distance between the driven pin and the rotation fulcrum of the transmission member is shorter when the blade is at the retracted position than when the blade is at the throttle position.   The diaphragm device according to any one of claims 1 to 5, wherein the driven pin reciprocates part of the cam groove while the drive ring rotates in a predetermined direction.   The driven pin reciprocates part of the cam groove while the drive ring rotates so that the blade moves from the throttle position to the retracted position. Aperture device.   The diaphragm device according to claim 6, wherein the driven pin abuts on one end of the cam groove while the drive ring rotates in a predetermined direction, and thereafter leaves the one end.   9. The aperture device according to claim 1, wherein the transmission member has flexibility.

Images